Airbreathing propulsion assisted gun-launched projectiles

Abstract

An air-breathing, propulsion-assisted projectile designed to be rocket or gun launched and capable of accelerating to hypersonic velocities includes a body having an encompassing cowl, an air compression section, an engine assembly located adjacent the air compression section, and a nozzle section located adjacent the engine assembly. The engine assembly includes apparatus for fuel storage and delivery to a combustion region. The rear end portion of the cowl is configured to direct the exiting combusted air-and-fuel mixture over the nozzle section of the body.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. An airbreathing propulsion-assisted projectile adapted to be fired from a gun at velocities greater than Mach 1, comprising: a body, including an external compression section, an internal compression section, a combustion section and a nozzle section having an external diameter,   a fuel supply isolated from said combustion section,   means for directing ambient fluid to said combustion section of the body,   said directing means and said body cooperating with the ambient fluid to produce thrust greater than drag when said projectile travels at velocities greater than Mach 1, and   a plurality of circumferentially spaced stabilization fins located within said external diameter of said nozzle section of said body to protect said fins from the gun barrel walls during firing of the projectile from said gun.   
     
     
       2. The projectile of claim 1, wherein said internal compression section defines a passageway having an internal contraction ratio greater than one. 
     
     
       3. The projectile of claim 1, and further including means for providing fuel at said combustor section. 
     
     
       4. The projectile of claim 1, and further including a sabot assembly releasably secured to the rear portion of said body, said sabot assembly including a plurality of elements which are joined together about the body rear portion and form a housing for protecting said body rear portion from explosive gases in the barrel of said gun. 
     
     
       5. The projectile of claim 4, and further including means for providing fuel at said combustor section, and   means, coupled with at least one of said plurality of elements, for initiating operation of said fuel providing means when said plurality of elements separate from said projectile as it exits from said gun barrel.   
     
     
       6. The projectile of claim 1, wherein said body further includes a payload compartment. 
     
     
       7. The projectile of claim 3, wherein said fuel providing means comprise a source of fuel, control valves, fuel routing lines connecting the fuel source with the combustion section of the body. 
     
     
       8. The projectile of claim 1, wherein said nozzle section includes an internal expansion surface and an external expansion surface. 
     
     
       9. An airbreathing propulsion-assisted projectile adapted to be fired from a gun and capable of travel at velocities greater than Mach 1, comprising: an engine having a fixed geometry flowpath for generating thrust greater than drag so that said projectile accelerates to hypersonic velocities.   
     
     
       10. The projectile of claim 9, wherein said engine comprises first engine means for compressing ambient air flowing past said projectile, channeling said compressed air through a passageway, combusting said channeled air, and expanding said combusted air in a first ramjet mode of operation, and   second engine means for compressing ambient air, channeling said compressed air through said passageway, combusting said channeled air, and expanding said combusted air in a second scramjet mode of operation.   
     
     
       11. The projectile of claim 10, said flowpath including fixed geometry compression and combustion sections for transitioning said mode of operation from said first ramjet mode of operation to said second scramjet mode of operation during the operative cycle of said engine. 
     
     
       12. The projectile of claim 11, wherein said transitioning means comprises means for operating both the ramjet engine mode and the scramjet engine mode simultaneously. 
     
     
       13. The projectile of claim 9, wherein said engine comprises ramjet engine means and scramjet engine means, and further comprising means for transitioning the mode of operation of said engine from the ramjet engine mode of operation to the scramjet mode of operation during the operative cycle of said engine. 
     
     
       14. The projectile of claim 13, wherein said transitioning means comprises means for operating both the ramjet engine mode and the scramjet engine mode simultaneously. 
     
     
       15. An airbreathing propulsion-assisted projectile adapted to be fired from a gun and capable of travel at velocities greater than Mach 1, comprising: a body having an exterior surface,   engine means disposed about said exterior surface of said body and including a combustion section,   a fuel supply within the body and isolated from said combustion section, and   a compression section external to the body and having an internal contraction ratio greater than one, whereby said projectile generates thrust greater than drag and therefore accelerates during its engine operation cycle.   
     
     
       16. The airbreathing propulsion assisted gun-launched projectile of claim 15, and further comprising annular cowl means, said cowl means and the exterior surface of said body defining an interior flowpath. 
     
     
       17. The airbreathing propulsion assisted gun-launched projectile of claim 16, wherein fuel is supplied from said fuel supply to said internal flowpath during operation of said engine. 
     
     
       18. The airbreathing propulsion assisted gun-launched projectile of claim 17, said flowpath includes an inlet having a contraction ratio greater than one, an isolator, a combustor and an internal nozzle, and said flowpath enables operation of the projectile in a ramjet mode, a scramjet mode or a combination of ramjet and scramjet modes. 
     
     
       19. The airbreathing propulsion assisted gun-launched projectile of claim 18, wherein said body further includes fuel injection means, and the operating mode of the projectile is dependent on the velocity of the projectile through the ambient fluid and the location of fuel introduced into the flowpath by the fuel injection means. 
     
     
       20. The airbreathing propulsion assisted gun-launched projectile of claim 13, wherein said body further comprises a tank for holding said fuel supply, fuel pressurizing means, fuel injectors, fuel lines coupling said tank with said injectors, valve means coupled with said fuel lines for selectively permitting delivery of fuel from said tank to said injectors, and pressure equalizing manifold means between said injectors and said valve means. 
     
     
       21. The airbreathing propulsion assisted gun-launched projectile of claim 20, wherein said valve means further functions to permit the loading of fuel into said tank. 
     
     
       22. The airbreathing propulsion assisted gun-launched projectile of claim 20, wherein said fuel lines are routed very close to the exterior surface of said body at said combustion section to cool said surface and impart heat to the fuel in said lines prior to the fuel reaching said injectors. 
     
     
       23. The airbreathing propulsion assisted gun-launched projectile of claim 20, and further including a fuel tank pressurization system for imparting pressure on said body of fuel in said tank to force said fuel through the lines to said injectors. 
     
     
       24. An airbreathing propulsion-assisted projectile capable of travel at velocities greater than Mach 1, comprising: an engine for generating thrust greater than drag so that said projectile accelerates to hypersonic velocities, wherein said engine includes a nozzle section having an internal expansion surface and an external expansion surface.   
     
     
       25. An airbreathing propulsion assisted gun-launched projectile, comprising: a body having an internal flowpath with a fixed geometry, said flowpath including an inlet having a contraction ratio greater than one, an isolator, a combustor and an internal nozzle,   said flowpath enabling operation of the projectile in a ramjet mode, a scramjet mode or a combination of ramjet and scramjet modes.   
     
     
       26. The projectile of claim 25, and further including a sabot assembly releasably secured to a rear portion of said body, said sabot assembly including a plurality of elements which join together to form a protective housing for said body rear portion. 
     
     
       27. The airbreathing projectile of claim 25, wherein said body further includes fuel injection means, and the operating mode of the projectile is dependent on the velocity of the projectile through the ambient fluid and the location of fuel introduced into the flowpath by the fuel injection means. 
     
     
       28. The airbreathing projectile of claim 25, wherein said body further includes means for compressing ambient air, a cowl surrounding the body downstream of said compressing means, fuel injection means, and fuel supply means isolated from said internal flowpath, said cowl including means for creating defined flows of said compressed ambient air and means for routing said flows from said inlet to said combustor, and wherein said fuel injection means communicates said fuel supply with said combustor.   
     
     
       29. The airbreathing projectile of claim 28, wherein said internal nozzle comprises fluid expansion means at the aft end of said cowl. 
     
     
       30. The airbreathing projectile of claim 29, wherein said body further includes fluid expansion means aft of said cowl.